Composite metal



July 28, 1925; I

- c. STEENSTRUP COMPOSIPIE METAL Filed March so, 1925 I im/en' jov; Christian Steehst'rup.

b $41,?! J j His Attrn e y.

' Pat'entedJuly 2 ,1925.

W E S AZTES E 1;:amen i CHRISTIAN STEEN'STRUP, or SICI-I-EQTEGTADY, NEW YORK, as srenon "ro GENERAL I V ELEC RIC COMPANY; A CORPORATION or NEW YORK. s

- COMPOSITE METAL.

Application filed March 30, 1923. Serial No. 628,926.

i To all whom it may concern:

Be' it known that I, CHRISTIAN I ing'in Schenectady, "county of Schenectady,

tion.

and State ofNew York, have invented certain new and useful Improvements in Composite Metals, of which the following isa specifica- I have invented or. discovered a composite metal of relatively high tensile strength which is capable of wide application in the mechanical and electrical arts and have. also invented or discovered amethod of mak1ng the same. Y

I In carrying out my invention, two metals are employed, one, whichmay be termed the base material and the other the void-filling 1 t'ainer. 'In some casesit may be desirableto and fusing material, the latter having a lower melting point than the former.. In

practicing the invention" according to: the

'- bestmethodknown to me, mild steel, "prefe *erablyhavinga low carbon content, is em; 7 ployed for the base materia'hand in' the form n of relatively small vpieoesor particles which are intheirnature selfpacking. By this is meant that the'particles or pieces are of such j 7 --irregular metal particles do not make'a satisr shape orcharacter that when poured into thereof and. completely thesameQ In this resp'ect they act in the same manneras ordinary lead shot when pour-ed into a con- I jar the'container by some external meansto facilitate the settling of thepieces. To ob til tain this self-packing" feature one simple 7 way, for example, "is to makerthepiec'es as nearly as possible in the form of small spheres, balls or shot ehaving relatively v 'smooth surfaces but itris not necessary that they be true spheres or balls although they are the best for the purpose. The nearer the 1 pieces are to. true spheres the smaller' will be the aggregate of the voids in the mass which is the thing to be desired, and the more dense and homogeneous will be the final product.

For the. sake ofconvenience, I shall, hereafter refer to these small, smooth particles as shot but without limitation, however, to true spheres or to truly round particles or pieces.

The size of the shot may be varied within quite wide limits, so longas the voidsbetween-them when assembledinto a mass are 7 V of a capillary nature. In-some cases it may v STEENj; j fyiE-iTRUP, a citizen of'the United States,,residbe found advantageous to use various sizes.

Whenthis' is'done the smaller shot are preferably of such size'that theys bi y fill the voids between the larger ones. Under these conditions the shot'should be thors container v I A V WVhi'l'e the shot may be "very small they are nevertheless of appreciable size, and as bearing on thispoint I have discovered that in the course of the development of my inventionpowdered metal is not satisfactory whether it be placed loosely in-a container or subjected to a substantial pressure; In the former case the finished material shrinks '55 of shot in the same finished article or piece. f

f oughly mixed 'beforefbeing poured intothe and cracks and in} the latter caserthe void r filling and fusing material does not properly-I penetrate the mass." This is due to the fact that as the void-filling'. material beginsito pletepenetration can" takeplace. "I have also found that iron-filings and other small,

factory material onaccount of the shrink-1 age, the result being much the same as that, 1

obtained with loose powder Further, the

final product is in no casedens'e and homo-- gen'eous.

These selfpacking particles or pieces be definitely formedor made in, any desired way, one of which is'as follows':-A' closed tank of suitable size is provided' which is 7 partly filled with water; A small stream of molten metal is poured into the tank from a suitable source through 'asuitable nozzle; Inthe'side ofthe taiilradjacent to the descendingv stream of molten metal and above the water level is a-second nozzle through; whichsteam or some reducing or neutral gas at fairly high velocity is'dischargedin such ticles in their travel through space are formed into shot and on account of their greater weight drop into the water while the Y 7 ed ontlet, either tothe' atmospherelin thev ll gas is permitted toescape through a restrictcase of steam or in the case of a neutral or reducing gas to a pump which returns it to the source of supply. The gas and water serve to wholly or largely prevent oxldation of the shot.

Material secured in this manner will contain some hollow or imperfect shot, some slag or other impurities. The undeslrable material is removed by a separator of any desired character, after which the shot are subjected to heat to dry them. It is also desirable in the case of steel to pass the shot through a hydrogen furnace to reduce any oxide thereon and also through an apparatus for grading them so that those used in any particular job may be of predetermined size. Shot made in this manner are very small and will run freely into any chamber or recess much the same as ordinary lead shot will.

Care should be exercised to see that the void-filling and fusing metal is free of impurities, especially when copper is used which I prefer where the base material is of mild steel. The ordinary commercial grade of copper contains some impurities which should be eliminated before use if the best results are to be obtained. These impurities manifest themselves chiefly in the form of gas which is liable to be trapped in the voids and; cause, imperfections in the finished product, and under some conditions may actually cause a displacement of the shot. I have found that boronizcd copper is suitable for the purpose, also copper which has been treated long enough in a hydrogen furnace to drive off most if not all of the impurities. The copper when in the proper state is preferably cut up into small pieces for convenience in handling and distributing. The amount of copper used should be sufficient to fill the voids and in any given case can readily be ascertained by simple experiment. The steel shot and the copper are unmixed in the container because when mixed the gases which are formed cause pockets in the finished product or else cause displacement of the shot or both. By placing the copper on top of the shot the ses are liberated outside and at v u 0 hence are not carried lnto the base materlal.

The chambered receptacle or container for the base material may be made in a variety of ways depending on the nature of the finished product. It may be made wholly of thin sheet metal, such as steel, or of heat resisting material such as asbestos or of a compound containing asbestos. The character terial, said materials and container being at room temperature. The container and its contents are then placed in a closed furnace in which a supply of hydrogen or other selected gas is constantly maintained. The furnace is then heated to a temperature sufliciently high to cause the void-filling and fusing metal to melt but not the base material. When this temperature is reached, (and it can readily be observed by ordinary sight tubes in the furnace) the fusing metal flows by capillary action into the voids and fills them. Any excess may be drained off by providing small drains in the bottom of the container. By preference the temperature of the furnace and its contents after the operation. is completed, is reduced rather rapidly at the start during which time the fusionof the steel shot and copper is completed, after which the cooling takes place more gradually. During the fusing operation a certain amount of alloyage of the two metals takes place, which increases the strength of the finished product.

One very great advantage flowing from my invention is the low cost of production. This will be apparent from the fact that the steel. used in making the shot may be scrap material or it may be in. the form of steel pigs or billets received directly from the steel makers and before any work is. done thereon. The apparatus used in, making the shot is very simple and the cost thereof is not much greater than that of the raw material. To reduce the amount of shot required, especially in making large pieces, p1eces of steel or scrap material may be employed which are placed in the container before the shot is poured in.

The fact that copper is used to fuse the steel shot very naturally raises the presumptlon that the finished product would have about the same strength as copper. I have found, however, by suitable tests that the finished product has practically the same tensile strength as that of mild steel, and that it may beemployed in a great many cases as a substitute therefor, and for some purposes is vastly superior thereto. For example, in uniting two or more separate pieces of metal, and in making structures having articles embedded therein.

The resulting product having as it does the general characteristics of mild steel may be subsequently treated in much the same way, that is to say, it may be rolled hot or cold, swaged, forged, machined or ground by the usual and ordinary means.

In the following description I have set forth as illustrations but not as limitations, some of the many uses to which my invention is applicable.

In the accompanying drawing, Fig. l shows a means for making up a flat slab, plate or bar of my improved material; Fig.

' ishowssome oli the f steel shot. onfagreatly "exaggerated scale used as the base material 3' I Fig. 3 shows a flat plateniadezofqnyx'imiw 3 proved material having an' articleembedded' -th'erein,fandF1g. 4 shows a means for uniti ing' twopieces .of metaliwith my improv d material. I o

' 'Tofform a slab, plate, baror other. shape a container 5 of any suitable size or'shape is provided.;- .Itfmay be: formed Wholly of 'inetal, ofheat-resisting materiahor a combination of both. The. shot 6" are poured into the chamber of the container and caused.

' shot appear in cross section.

to settle. Fig.2 maybe takenas'illustrw tive, onan exaggerated. scale, of the way the Small pieces I "of copper 7 i in suitable quantity are then placed on top of the shot, afterwhich'the container and its contents are placed in a I 20 closed hydrogen furnace: and subjected to. a

temperature high enough to meltthe copper v and cause it to fuse the shot to each other and to the walls of the container, but not one which is notfluid-tight so that any excess of, copper may. drain therefrom. For example, in the container shown 1n Fig. 1,

at the lower cornerswhere the verticalsides join the bottonnopen drains-7 may be pro:-

videdfor the'purpose o t-permitting the ex 7 V g o V p V v If desired, the opposite ends of the parts;

cess copperto draintherefrom; 'I

Fig.- '3 illustrates-a plate structure."designed to have embedded therein anelement or article, of definite shape such. as a bar. or rod 81 of any desired prose-section.' Itfmay 'be' wholly or partly :embe'dded depending upon the use to 'which the. final structure is to be put. As shown, both ends of the article project throughandbeyond the walls of the container. .In such a case the article. is insertedin'the containerand suitably-supported after-which "theremainder of the chamber is filled withsteel shot; Theele:

ment maybe supported Wholly by the walls. of the container or the. container may be partly filled with. shot, and the element placed on top thereof, after which the container is filled to the desired level. The subsequent'treatment in the hydrogen-furnace is the same as previously described. In the fusing operation the shot are fused to each other, to the walls of the container, and also to the wall or walls of theembedded article thereby making a very solid construction.

' Such a construction is well ,adapted-;to -form' anchoring-devices for bar's,jrods and the like since it permits of the use of. standard stock shapes. The composite materialflmay also" be considered as. aholderior the'article 8.

In Fig. .4 I have shown how -two forfmore pieces of metal may be united by my improved composite material; Thelunionber i tween any-twopieces.may take'fplace at one side,v at the endp'or at both sides andiend;

Thisfeature of my invention'findsparticn- '70 V to unite one partto another, which part by 7 reason of its use has to be of particular lar applicationjin the-arts where it is desired shapeand which must not be distorted in any. way. In the figure'9 indicatesiasrela- '75 r tively heavy member such as .a cast steel ring, and 10 a rather thin steel part which has been previously given some exact shape asshown and which must be united tothe memberlwithout any distortion,.and which must occupy a definite position with respect tosaid member. In such a case achannel or slot 11 is provided in the'member for. the

reception of one end of thepart 10.. Iffa large number of such pieces are to; berunit ed to the member a correspondingnumber of slots are provided. These slots are substan tially larger than theinserted euds of the" pieces 10 so as to form-a chamber thereof.

As a general propositionthe lowerwallot 6 the piecesiand someportiohs ofthe walls'or 7 other means may be employed to. hold the;

the slot will determine the lower position of part in its proper vertical position, In the present illustration the chamber for theend of each part 10'is completed bythe pieces 12 ing material-such as asbestos, .Theymay be held in placeby friction orother suitable dicated by the dottedline 14. In such a construction the two 'members are cast separately and hence any shrinkages-or distorof my improved composite metal.

After 'the partsare arranged as described and 13 which arepreferably of heat-resist 1 tions take placebefore ,they ar'e united with,

the parts 10.: It'is'ofcourse evident. that g the parts. orelements 10 may be'supported' y g' at one or both ends. his also evident'that either orboth'members may be made wholly f 'j i steel shot are pouredinto each chamber completely filling ,the' same. amount of copperis then distributed over the shot after which the structure is treated. in a hydrogen furnacedas previously described- V V I believe it is broadly new with me in the manufacture of composite metal to :utilize self-packing orfreely-flowingparticles or f The necessary I pieces of metal of any kind as the base mai of lower melting point and of such char;-

have described steel shot for thebaseLma gimbt ter'ial in combination with an added metal terial and copper as the void-filling and fusing metal since the composite metal thus formed is capable of very wide application in the arts. As another illustration of my invention when applied more especially to the electrical art, the self-packing particles or pieces may be made of copper and the void-filling and fusing material of silver or spelter. The advantage of composite ma terial of this character resides in the fact that its electrical conductivity is high which renders it available for many purposes and especially for uniting two or more parts through which current flows, as for example, in the case of a squirrel cage rotor where it is desired to unite the conductors carried by the rotor with the short-circuiting end rings.

What I claim as new and desire to secure by Letters Patent of the United States, is 2- 1. A composite material comprising a base of self-packing metal particles, and a void filling metal of a lower melting point than the metal particles which unites said particles into an integral mass.

2. A composite material comprising a base of self-packing'metal particles having voids of a capillary nature between them and a void-filling metal having a lower melting point than the metal particles which fills said voids and unites said particles into a dense, integral mass.

3. A composite metal comprising a base metal in the form of small shot, and a second metal having a lower melting point than the first which fills the voids between the shot and unites them into an integral mass.

4. A composite material comprising abase of steel shot and a second metal having a lower melting point thanthe base which fills the voids in said'base and unites the shot composing the same into an. integral mass.

5. A composite metal comprising a base metal in the form of small mild steel shot, and copper filling the voids between the shot and uniting said shot into an integral mass.

6. The method of forming a metallic body which comprises assembling self-packing metal paiticles into a body of the desired shape, adding another metal of lower melting point in sufiicient amount to fill the voids between said particles, and subjecting the same to a temperature sufiiciently high-to cause fusion of said particles and the added metal.

7. The method of forming a metal body which comprises assembling self-packing particles into a body of the desired shape, adding another metal of lower melting point and in suificient amount to fill the voids between said particles, inserting the body thus formed in a closed furnace in which a supply of. selected gas is maintained, and subjecting it to a temperature which is above the melting point of the added metal and below that of the metal particles, to cause fusion of the metals.

8. The method of forming a metallic body which comprises assembling small shot into a body of the desired shape and size, the voids between the shot being of a capillary nature, adding another metal in sufficient amount to fill the voids between. the shot, and subjecting the same when in the presence of a selected gas to a temperature sufliciently high to cause fusion of the shot and the added metal.

9. The combination of a. base comprising self-packing metal particles, a metal filling the voids in the base metal which metal has a lower melting point than the base metal, and a metallic article which is wholly or partly embedded in said base, said voidfilling metal uniting" the particles and the article into an integral structure.

10. The combination of a base comprising self-packing metal particles, copper filling the voids in the base material and which has a lower melting point than the base material, and a metallic article which is wholly or partly embedded in'said base, said copper uniting the base and article into an integral structure.

11. The combination of a base material in the form of steel shot, a metal filling the voids in the base and which has a lower melting point than the base, and a metallic article which is wholly or partly embedded in said base, said base and article being united into an integral structure by the voidfilling metal.

12. Two or more separate pieces of metal arranged in juxtaposition in combination with a composite metal. comprising selfpacking metal particles which are located between the pieces, and a metal filling the voids between the particles, said void-filling metal uniting the base material and said pieces into an integral structure.

18. Two or more separate pieces of metal arranged in juxtaposition but separated by a small space, in combination with a composite metal comprising small shot which fill the space between the pieces, and a metal filling the voids between the shot, said metal uniting said-pieces and shot into an integral structure.

1ft. Two or more separate pieces of metal arranged in juxtaposition but separated by a small space, in combination with a means uniting them, said means comprising small steel shot which fill the space between the pieces, and copper filling the voids between the shot and uniting said piecesand' shot into an integral structure.

15. The method of uniting two metal pieces which comprises assembling them in the desired relation one to the other with a chamber between, fillingthe chamber with cient metal to fill the' voids between the particles, and subjecting-said added metal to a temperature sufliciently high to causeit.

"between the shot, and subjecting the added if metal to a temperature sufiiciently high to j a tween the shot, said 'material having a strength substantially equal to that ofmildj cause it tofill'the' voids and j fuse thepieces and particles together. i

juxtaposition with a limited. space between ing metal particles, adding another metal in sufiicient amount tofill the Voids between the particles, placing the structure thus assem bled'in a closed furnace in which a supply of selected gas is constantly maintained, and

subjecting the same to a temperature sufliciently high to melt the added metal and V I cause it to fuse said elements and the par- 7 ticles into a unitary structure.

body which comprises" assembling selfpa'cking metal particles in a containerwhich has an open drain, said particles having ifvoids' of a capillary nature, adding another filling metal.-

7, V. A composite material'comprisingself- .packingmetal pieces forming the base therei self-packing metal particles, adding shot, adding sufficient metal to fill 'thevoids a, 17. The method of. uniting metal pieces. which comprises assembling the pieces in them, filling said space with small self-pack 18. The method of forming a metallic" -F materialis greater than that of the void- 7 {If of and a second metalset fromrfusion' ing the voids between. said-,piecesandflu'nit-' p ing them intolanintegral j mass, said material having a strength greater than that of the void-filling metal. L T

second metal set from fusion in thevoids composite material comprising I metal shot in packed formation, united by a I between the shot, said material havinga second metal." H I composite material comprising steel 1 shot in packed formation, intimately united byfcopper set from fusion in the. voids besteel. 1 r

'23; A composite'material comprising; base of self-packing metal particleshavingfi voids of a capillary nature, and a metal fills" ing the I voids which has a 'lOWer melting point than the particles and which. so inti; "mately unites the particles that the strength i of the material is greater than that 'of thc void-filling metal. I

2 1E. A composite material comprising, as 7 s a preponderant. constituent, packed metal 1 '75 particles having voids of a capillary nature,

and a metal filling the voids which has a.

lower melting point than the particles and which .is-alloyed with the particles to a certain'eXtent, saidfmaterial having a strength which is approximately: the same asthat; of

the preponderant constituent.

members and a metalhaving a lower melting point than the pieces which so intimately-unites them with the members that CHRISTIAN 'sTEENsTRUr; i 

